Improvement in telephone and microphone switches



G. ANDERSON & A. E. BRIGGS. Telephone and Microphone Switch.

No. 218,362. Patented Aug. 12,1879.

Ground L ke firownil 7 "$5518, FHOTO-LITHOGRAPHER, WASHINGTON. D C.

- oHARLEshNDEnsoN I I UNiTED Three IMPROVEMENT IN TELEPHONESpecification forming part of Letters Patent No. 218,362, dated August12, 1879 I June 3, 1879.

To all whom it may concern;

Be ifiknown that we, OHARL s ANDERSON and ARTHUR E. BRIGGS, both ofCincinnati, in the county of Hamilton and State of Qhio, have invented acertain new andfuseful Improvement in Telephone and Microphone Switches;and we do hereby declare the following to be a full, clear, andexa'cttdescription of the same, reference being had to the accompanyingdrawin' gs, forming part of this specification, in whic 5- ,5

Figure 1 is a plan View of a telephone-box with the cover'open and withamicrophone attached. Fig. 2 is a similar .view with the cover closed,and Figl' 3 is a perspectiveview of the switch and its connectionswiththe telephone separated from the switch-hook.

,Similar lettersof reference in the several figures denote the sameparts.

c Our invention has for its object to provide an improved switch fortelephone-lines and for a telephone line with microphones attached; andto this end it consists in a springswitch connected with each telephoneappa Q, ratus, adap ted to support the weight of the telephone, forthepurpose of breaking the tele phone and microphone connections withthe, line, and, when relieved of the weight of the telephone, toautomatically make said connections, as I will now'proceed to describe.

In the accompanying drawings, A repre? sents a telephonebox, containinga magnetoengine, B, and thebinding -iposts l3 for line and ground wires.0 is the cover, hinged to the box by five hinges D E F G H, respect'ively. I are electro magnets, mounted upon the inside of the cover, soas to enter the box when the cover is closed. The armature of thesemagnets is provided with a bellarm, which projects through the coverbetween two bells, K K, on the outside, for sounding each alternatelywhen a call is made upon the line.

L is the microphone, and M the battery thereof. These several parts arenot new in telephone lines, but are at present in use in various partsof the country.

N N are line-wires extending each side the box, if thelatterbe at anintermediate station, a center-post being placed between the twobinding-posts of the line-wires to receive the ground-wire 0, if used.

PATENT AND ARTHUR E. BRIGGS, or oINoIN NAfTIQoHIo, ASSIGNORS TO rosr &oo.

AND MICROPHONE fsfWiToHEs.

application filed The magneto-engine, as well as the electromagnets, isinterposed in the main line, for the purpose of establishing a cu'rrentor circuit, the interruptions or breakings of which sound the call uponthe bells, Toefi'ect-ithis the wires N from the poles of the engine ex-D, and thence to a bindingpost in the box.

The connection from the plate P to the 'line .is through the switch S,the construction of which I will presently describe ,thence, by a flatspring, T, on the cover and a short wire, to the hinge G, which, in itsturn, is joined to the line by a wire, N extending within the box' toone of the binding-posts B1, i

To create a current upon the line thus established, the crank U on the[outside of the box is turned, and, through friction-pulleys on thecrank-shaft and the shaft of the armature,

motion is communicated to thelatter torotate it in its cylinder. Thisestablishes a short circuit in the usual manner, the interruptions ofwhich cause the bells to sound, and the interruptions are produced bypushing a button, V, projecting from the front of the cover and hearingagainst the break-spring Q, as shown by dotted lines, Fig. 1, each pushof the button lifting the spring from the plate P, and thus breaking theshort circuit and throwing the current to line. I

The primary current from the microphone is from the battery to the lowerhinge, H; thence to a lower plate, W, on the cover; thence along theswitch S and spring T to thehinge G;

,and from the hinge, through the wire N to its binding-post B From thebinding-post it passes along the wire N to a post, B in the lower end ofthe box, thence to the microphone, and from there to the opposite poleof the battery. Y

The induced current from the. microphone passes to the line along wiresN N to binding-posts B B in the cover, the upper post being joined by awire, N, on the cover with the line-wire N from the electro-magnet. Thelower post, B is connected by a wire, N with the lower of twobinding-posts, B B, near the opposite edge of the cover, and to theseposts the telephone X is attached. The upper post, B, is connected by awire, N, with a plate, Y, secured to the cover under the switch, asshown. The induced current is employed for working the telephone, andtransmits the telephonic connections in both directions from theapparatus on the line, as will be readily understood.

The switch S, which, with its connections, forms the subject of ourinvention, is composed of a rigid bar of metal, a, pivoted near itslower end between the ears of a plate, b, secured to the inside of thecover, and provided with a forked book, 0, projectingthrough to thefront ofthe cover. The upper and lower ends are adapted to makeconnection with the plates P Y on the cover when the bifurcated hook isoperated, the contact-surfaces being faced with platinum to insure aperfect connection. The spring T serves to hold the upper end of theswitch off the plate P and its lower end on the plate W.

The object in bifurcating the hook is to suspend the telephone betweenits arms, so that the weight thus applied shall overcome the tension ofthe spring J and swing the switch so that its lower end shall breakconnection with the plate Y, thus cutting out the telephone andmicrophone, and throw its upper end down upon the plate P, to establishthe circuit for sending the calls upon the line. The lower end of thebar :1 also carries a thin metallic spring, d, to make themicrophone-connection with the plate W on the cover when the spring isin contact with such plate, their contact-surfaces being faced withplatinum.

The distance from the pivot of the switch to the lower plate, W, is sogreat that if the switch were made long enough to cover it, itsintermediate point could not come in contact with the plate Y of thetelephonecircuit;

'hence the employment of the spring becomes necessary, because it willyield when it touches the plate W, and allow the intermediateswitchpoint to bear upon the plate Y at the same time.

When the line is not in use for transmitting intelligence, the telephoneis hung upon the forks of the switch, thus breaking the telephone andmicrophone connections.

When a call is to be made to a distant station, the crank is turned andthe push-button operated, as above described; and when it is desired tocommunicate with a distant station, the operation of the crank isstopped and the telephone detached from the books. The switch, thusrelieved of its weight, is automatically operated by the spring T, tobreak the connection with the plate P, thus cutting out the callmechanism, and to make the connection with the plates Y W, to establishthe telephone and microphone circuits for receiving and transmitting thecommunication.

When a microphoneis not employed with the telephone-line, the switch maybe,.made without the spring, in which case a slight change in thearrangement of the telephone-wires is necessarythat is to say, themicrophonewires are left 011', and the two posts B electricallyconnected.

Having thus described our invention, we claim as new- 1. Thespring-switch S, adapted to support the telephone, combined with thestops of the telephone and microphone lines, whereby, when the telephoneis removed from theswitch, the local or primary circuit of themicrophone is connected, and the secondary circuit of the microphone putupon the main line and through the telephone, substantially asdescribed, for the purpose specified.

2. The combination of the spring-switch and spring T with the stops W Yof the telephone and microphone lines, and the stop P and break-spring Qof the magneto device, substantially as described, for the purposespecitied.

In testimony of which invention we hereunto set our hands this 22d dayof May, A. D. 1879.

CHARLES ANDERSON. ARTHUR E. BRIGGS.

Witnesses:

E. A. ELLSWORTH, W. BLACKSTOCK.

